Etiology

Congenital

• Heterotaxy Syndrome
• Isolated Congenital Asplenia

Acquired

Surgical Splenectomy (see Splenectomy, [[Splenectomy]])

• Typical Indications for Surgical Splenectomy
  • Immune Thrombocytopenic Purpura (ITP) (see Immune Thrombocytopenic Purpura, [[Immune Thrombocytopenic Purpura]])
  • Hereditary Spherocytosis (see Hereditary Spherocytosis, [[Hereditary Spherocytosis]])
  • Beta Thalassemia Major (see Thalassemias, [[Thalassemias]])
  • Traumatic Splenic Rupture
  • Tumor-Related Splenic Rupture

Functional Asplenia

• Sickle Cell Disease (see Sickle Cell Disease, [[Sickle Cell Disease]]): auto-splenectomy occurs commonly during childhood (due to recurrent splenic infarcts)

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Clinical Manifestations of Hyposplenism/Asplenia

Hematologic Manifestations

• Decreased Uptake of Radioactive Colloid/Red Blood Cells/Leukocytes/Platelets by the Spleen: in cases with splenic hypofunction, but an intact spleen
• Heinz Bodies within Circulating Red Blood Cells (see Peripheral Blood Smear, [[Peripheral Blood Smear]]): seen by supravital dye stain
• Howell-Jolly Bodies within Circulating Red Blood Cells (see Peripheral Blood Smear, [[Peripheral Blood Smear]])
  • Howell-Jolly Bodies Can Be Quantitated to Provide an Estimate of the Degree of Splenic Hypofunction
• Misshapen Red Blood Cells (see Peripheral Blood Smear, [[Peripheral Blood Smear]])
• Red Blood Cells with “Pits”: seen by interference microscopy
  • Quantification of Pitted Red Blood Cells Can Provide an Estimate of the Amount of Splenic Tissue Remaining Following Splenectomy
• Red Blood Cells with Decreased Deformability
• Target Cells (see Peripheral Blood Smear, [[Peripheral Blood Smear]])
• Mild Leukocytosis (see Leukocytosis, [[Leukocytosis]])
• Mild Thrombocytosis (see Thrombocytosis, [[Thrombocytosis]])

Infectious Manifestations

• Increased Risk for Bacteremia/Sepsis with Capnocytophaga Canimorsus (see Capnocytophaga Canimorsus, [[Capnocytophaga Canimorsus]])
  • Epidemiologic Exposure: dog bite
• Increased Risk for Infection with Encapsulated Organisms (see Bacteria and Fungi, [[Bacteria + Fungi]]):
  • Haemophilus Influenzae (see Haemophilus Influenzae, [[Haemophilus Influenzae]])
  • Neisseria Meningitidis (see Neisseria Meningitidis, [[Neisseria Meningitidis]])
  • Streptococcus Pneumoniae (see Streptococcus Pneumoniae, [[Streptococcus Pneumoniae]])

Pulmonary Manifestations

• Post-Splenectomy Pulmonary Hypertension (see Pulmonary Hypertension, [[Pulmonary Hypertension]])

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References

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